Weird fuzz/shading error on a render of a house model. Help?
The problem on the triangle of your house is that there are intersecting meshes. To fix the issue, go into edit mode and hit W>Remove Doubles. also make sure that you don't have an duplicate objects.

To fix the noise, change this setting:


The higher you set it, the less noise you will get, and the longer your render-times will become.